In the late 1990,flight attendants around the world noticed a dramatic increase in "air rage". This is the official term for what happens when someone becomes extremely angry or upset on a plan. These people may become so dangerously violent that the plane has to land somewhere and unload the passengers. Air rage may be the result of several factors. The general worsening of travel conditions in recent years has led to crowded planes and frequently delays. At the same time, airlines have generally reduced the amount of seat space for each passenger, so people are more likely to feel stressed and aggressive. One other factor, however, has nothing to do with the airline industry. Flight attendants say that very often the people wh become violent on planes have had too much alcohol to drink, either before the flight or on the plane